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Reactions of iron- and zinc-fuelled pyrotechnic systems

- Tribelhorn, Michael John

Authors: Tribelhorn, Michael John
Date: 1995
Subjects: Detonators Peroxides Chemistry, Analytic
Language: English
Type: Thesis , Doctoral , PhD
Identifier: vital:4341 , http://hdl.handle.net/10962/d1005003
Description: A major industrial use of pyrotechnic compositions is as delay fuses in electric detonators. Suitable delay times may be achieved through (i) choice of chemical components (ii) adjustment of composition of the system chosen and, finally, (iii) adjustment of the length of fuse used. This study forms part of a survey of binary fuel/oxidant combinations in an attempt to provide some fundamental information on the first step above: (i) choice of chemical components. The complete survey has included studies of a single fuel in combination with one of a variety of oxidants, and studies of the oxidation of one of several different fuels separately by barium peroxide and strontium peroxide. This study is part of this second approach and the fuels chosen were iron and zinc powders, mainly for chemical reasons (including the potential for use of thermomagnetometry on the iron systems), but also for possible environmental advantages. The mixed oxide products of pyrotechnic combustion could also have some scientific and/or commercial value. The techniques used included thermal analyses of mixtures and their individual components, and measurements of temperature-time profiles during combustion. Thermodynamic and kinetic information was obtained under a variety of conditions and scanning electron microscopy and X-ray diffraction and microprobe analyses provided additional information. Possible mechanisms of reactions are discussed in detail. The practical conclusions were that any potential use which the Fe/peroxide systems may have as delay compositions, with burning-rates of from 3-30 mm s⁻¹, is offset by the susceptibility of the oxidants to reaction with water and CO₂ in the atmosphere. The Zn/BaO₂ and Zn/SrO₂ systems did not burn under compaction, and combustion of uncompacted powders was erratic. Zinc liquid (and probably zinc vapour) take part in the reaction and the gaseous nature of the combustion makes zinc-fuelled pyrotechnic systems unsuitable for delay applications. All the techniques used showed the heterogeneity of the solid residues of combustion. If these residues were to be of any value, they would need further conventional treatment involving grinding of the residue, possible adjustment of compositions, and calcining to produce uniform materials.
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Date Issued: 1995

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Remora : implementing adaptive parallelism on a heterogeneous cluster of networked workstations

- Rehmet, Geoffrey Michael

Authors: Rehmet, Geoffrey Michael
Date: 1995
Subjects: LINDA (Computer system) , Local area networks (Computer networks) , Computer networks , Remora (Computer system)
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:4673 , http://hdl.handle.net/10962/d1006696 , LINDA (Computer system) , Local area networks (Computer networks) , Computer networks , Remora (Computer system)
Description: Computers connected to a local area network are often only fully utilized for short periods of time. In fact, most workstations are not used at all for a significant portion of the day. The combined "idle time" of the workstations on a network constitutes a significant computing resource, which is generally wasted. If harnessed properly, such a resource could constitute a cheap alternative to expensive high-performance computers. Adaptive parallelism refers to the parallel execution of a computation on a dynamically changing set of processors. This thesis investigates the viability of this approach as a vehicle to harness the "idle cycles" available on a heterogeneous cluster of networked computers. A system, called Remora, which implements adaptive parallelism via the Linda programming paradigm, is presented. Experiments, performed using Remora, show that adaptive parallelism provides an efficient vehicle for using idle processor cycles, without having an adverse effect on the tasks which constitute the normal workload of the computers being used.
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Date Issued: 1995

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Resource materials development in environmental education : Exploring some of the myths and tensions in participatory resource development in the We Care Primary Project

- Lotz-Sisitka, Heila

Authors: Lotz-Sisitka, Heila
Date: 1995
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/438792 , vital:73500 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137472"
Description: This paper on environmental education resource materials development represents some of my 'lived experience' (Malone, 1994:20) as a researcher involved in clarifying the processes of materials development for junior primary classrooms. The sites of inquiry, action and reflection have been focussed around the development of the We Care Primary materials, shifts in orientations to environmental education and current educational change.
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Date Issued: 1995

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Risk and benefit as functions of savings and loan clubs: an examination of the importance of rotating credit associations for poor women in Rhini

- Buijs, Gina

Authors: Buijs, Gina
Date: 1995
Subjects: Africans -- Economic conditions Rhini (Grahamstown, South Africa) -- Social conditions Savings and loan associations -- South Africa -- Grahamstown Savings and loan associations -- South Africa Urban poor -- South Africa Women -- South Africa -- Grahamstown -- Economic conditions Women -- South Africa -- Economic conditions Black people -- South Africa -- Grahamstown Grahamstown (South Africa) -- Economic conditions
Language: English
Type: Manuscript , Text
Identifier: http://hdl.handle.net/10962/2498 , vital:20298
Description: Paper presented at an ISER Seminar, 25th April 1995: This paper examines the implications of risk taking in the context of rotating credit associations popular among poor women in Rhini. Mary Douglas notes that in the 19th century when the theory of risk taking became important in economics, humans were thought to be risk averse because they chose according to a pleasure calculus. In the 18th century the idea of risk was neutral: it took account of the probability of gains and losses. The concept originally emerged in the 17th century in the context of gambling. Risk then means the probability of an event occurring, combined with the magnitude of the losses and gains which would be entailed. She comments (1992:31) that the evaluation of the outcome is a political, aesthetic and moral matter. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
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Date Issued: 1995

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Routing MIDI messages in a shared music studio environment

- Mosala, Thabo Jerry

Authors: Mosala, Thabo Jerry
Date: 1995
Subjects: MIDI (Standard) , Computer networks
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:4672 , http://hdl.handle.net/10962/d1006695 , MIDI (Standard) , Computer networks
Description: The Rhodes Computer Music Network (RHOCMN) is a network which allows main studio resources to be shared. RHOCMN is growing into a multi-workstation environment and additional devices are being incorporated into the system. A star configuration is used for transmitting MIDI from a MIDI patch bay to the workstations and MIDI devices. This imposes several disadvantages on the use of the studio, such as wiring problems. In a quest to avoid problems related to MIDI in RHOCMN, the MIDINet system was developed. The idea was to acquire a viable solution to MIDI's main problems which does not involve a redefinition of the MIDI specification.
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Date Issued: 1995

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SADTU News - A review of SADTU Congress

- SADTU

Authors: SADTU
Date: 1995
Subjects: SADTU
Language: English
Type: text
Identifier: http://hdl.handle.net/10962/118030 , vital:34586
Description: The Third SADTU Congress, held at the World Trade Centre in Kempton Park, was attended by over 800 delegates, representing 100 000 teachers country-wide. Delegates were elected at Branch level, ensuring grass roots participation in the highest decision making body of the Union. The Congress served to confirm SADTU’s position as the largest teacher Union in the country, and demonstrated a strongly unified focus around the theme: “Unionise and Reconstruct for Teacher Empowerment”. The success of any Congress must be measured against the aims it sets itself. Our Congress had two aims: to elect new leadership for the next two years, and to adopt resolutions which would inform the direction and programmes of the Union in this period. While we successfully completed the former task, we could only make a start on the second aspect - confirming the fact that the period we are entering is far more complex than before, and in need of extensive analysis and debate. We therefore mandated the SADTU National Council to formalise the adoption of resolutions arising from the reports. A Special National Council was convened on 25/26 August, with extended participation by regions, and the Congress report can now be finalised.
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Date Issued: 1995

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SADTU News - Model C Schools

- SADTU

Authors: SADTU
Date: 1995
Subjects: SADTU
Language: English
Type: text
Identifier: http://hdl.handle.net/10962/161012 , vital:40580
Description: Model C Schools have created great controversy in recent educational policy debate. SADTU has joined the fray in opposition to the retention of these schools. Model C is a particular type of state aided school which is different to state aided schools like the farm schools that came under the authority of the former black Department of Education and Training (DET). The latter schools were mostly poorly resourced and inadequately staffed. Model C schools are state aided schools that have governing bodies elected by the parents, with power over a number of key functions of the school. These include control over admissions policy, the power to charge compulsory school fees and to raise funds by other means (e.g. renting out the school's property), the power to decide how the school's money is to be spent (e.g. school maintenance, the hiring of additional teachers and other staff, the buying of books and equipment, and the power to exercise influence over the hiring and disciplining of teachers). The system is unique among state- aided schools in that Model Cs are all former state schools in the privileged white school system. Nearly all inherited a sound infrastructure provided largely by the state in the form of school buildings, grounds, libraries, laboratories etc. They also inherited a well qualified teaching staff, whose training (the best in the country) was also partly the result of public subsidies. Model C has several strengths which has led to the ongoing controversy. Parental participation in the schooling of their children has been mobilised. The governing bodies actually have power over important aspects of the school in contrast to the old comparatively toothless management councils. This, it appears, has ensured that parents, whether they approve of Model C or not, take them much more seriously since the governing bodies can take decisions which materially affect them and their children's education. In addition, this model has mobilised private resources for education and ensured that a relatively high level of provision can be maintained while state funding is decreased. Money thus saved by the state - reportedly about R1 billion - can be diverted to redressing the inadequacies of African education.
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Date Issued: 1995

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Seasonally monoestrous reproduction in the molossid bat, Tadarida aegyptiaca from low temperate latitudes (33 S) in South Africa

- Bernard, Ric T F, Tsita, Johannes N

Authors: Bernard, Ric T F , Tsita, Johannes N
Date: 1995
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/447333 , vital:74611 , https://doi.org/10.1080/02541858.1995.11448366
Description: A histological study of reproduction in Egyptian free-tailed bats (Tadarida aegyptiaca) Irom the Eastern Cape Province of South Alrica (c. 33°S) showed that females were seasonally monoestrous. Copulation, ovulation and lerlilizalion occurred in August, at the encf of winter, and births in December, after a four-month pregnancy. These results are compared with those of other molossid bats from tower latitudes in Africa. We conclude that the monoestrous habit of the Egyptian Iree-tailed bat at 33°S may be due to its relatively long pregnancy, and to the short summer period during which minimum temperatures are high enough to ensure an abundance of nocturnal flying insects.
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Date Issued: 1995

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Secondary school geography teachers' perceptions of the role of environmental education in geography with particular reference to Natal Education Department teachers

- Wassermann, Johannes Michiel

Authors: Wassermann, Johannes Michiel
Date: 1995
Subjects: Geography teachers -- South Africa -- KwaZulu-Natal -- Attitudes Environmental education -- South Africa -- KwaZulu-Natal
Language: English
Type: Thesis , Masters , MEd
Identifier: vital:1761 , http://hdl.handle.net/10962/d1003646
Description: Environmental Education (EE) as a development cannot be ignored by Geography or Geographers particularly since South Africa, as the rest of the world, is confronted by a looming environmental crisis. Geography is an environmental science concerned primarily with man-environment relationships using an environmental approach to develop the skills, knowledge, values and attitudes necessary for sustainable living. Geography has a vital role to play in addressing environmental issues. In formal education Geography teachers will be responsible for the implementation of such an approach. This study therefore investigates the perceptions of Natal Senior Secondary School Geography teachers regarding the role of EE in Geography. Questionnaires and semi-structured interviews were used to determine this. The study revealed that although these teachers are well qualified and motivated they had a limited grasp of the theory underpinning current EE and Geographical thinking. Recommendations are made for the development of an environmental approach in the teaching of Geography.
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Date Issued: 1995

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Sensitive high-performance liquid chromatographic determination of cyclizine and its demethylated metabolite, norcyclizine, in biological fluids using coulometric detection

- Walker, Roderick B, Kanfer, Isadore

Authors: Walker, Roderick B , Kanfer, Isadore
Date: 1995
Language: English
Type: text , Article
Identifier: vital:6452 , http://hdl.handle.net/10962/d1006640 , http://dx.doi.org/10.1016/0378-4347(95)00202-T
Description: An accurate, sensitive, selective and reproducible high-performance liquid chromatographic method with coulometric detection for the determination of cyclizine and its inactive demethylated metabolite, norcyclizine, in biological fluids has been developed. The drugs were separated using a custom packed reversed-phase C18 analytical column and phosphate buffer (0.05 M, pH 3)-acetonitrile (7:3) as mobile phase. The dual electrode coulometric detector was operated in the "oxidative-screen" mode with the upstream electrode (detector 1) set at 0.55 V and the downstream electrode (detector 2) set at 0.90 V. Serum and urine samples were prepared for analysis by solid-phase extraction, followed by a simple phase-separation step. The limit of quantitation was 1 ng/ml for both cyclizine and norcyclizine in serum and urine.
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Date Issued: 1995

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Southern African Journal of Gerontology, volume 4, number 1, April 1995

- Ferreira, Monica (editor), Møller, Valerie (editor), HSRC/UCT Centre for Gerontology

Authors: Ferreira, Monica (editor) , Møller, Valerie (editor) , HSRC/UCT Centre for Gerontology
Date: 1995
Subjects: Gerontology -- South Africa , Older people -- Care -- South Africa
Language: English
Type: Text
Identifier: vital:8070 , http://hdl.handle.net/10962/d1012862
Description: [From Editorial]The sixth number of SA. IG includes varied and interesting contributions which will appeal to researchers and practitioners alike. It is fitting that precisely a year after the first fully democratic elections were held in South Africa. an article by M0ller on voter education of older Africans should be included in this number. M0ller has captured the euphoria of the older first-time voters in her selection of quotations from media reports on the voting. She concludes in her article that for these older South Africans who waited over 40 years to be enfranchised, voting was experienced as a particularly fulfilling moment in their lives. In an original paper Burman examines the findings of a study on the nature and extent of child care rendered by older coloured women in the Cape Peninsula - either to grandchildren. or to the children of other relatives or non-relatives. Burman considers the economic implications of the care which the women provide and finds that very few benefit financially. On the contrary, she notes a downward, rather than an expected upward flow of wealth, whereby social old-age pensioners share their pension money with other members of the household, including the grandchildren for whom they care. Burman concludes that not only are intergenerational relations strengthened by older women remaining in the family structure and caring for young children but through their pensions they enjoy considerable status in the household. Three practice items are included in this number. Working within a social-work framework, Howes has developed a monitoring instrument for use in the case management of older clients in the community. She reviews recent literature on case management and introduces the concept to South African practitioners, indicating its potential usefulness in a restructured service-delivery system in South Africa. She argues that to address the backlog in service delivery in developing and rural communities. and in view of limited resources and other reasons which discourage institutional care. case management is a means of rendering and co-ordinating cost-effective care to older persons in the community. , Authors Amosun, Mazarire and Mawere examine the pattern of utilization of physiotherapy services by elderly Zimbabweans at a central hospital in Harare. They establish baseline data on the medical conditions for which the patients received physiotherapy. The authors highlight the need for adequate information in these areas in African countries. In the third practice item, Tooke raises the issue of developing and providing training for carers in homes for the aged. He reports on the training methodology which he has developed for this category of worker, and calls for the setting of standards for such training and the institution of procedures to ensure that standardized training of carers is carried out in homes. The poor training of carers. or a lack of training for this cadre of workers has been mooted as a factor which contributes to the mis-treatment or abuse of residents in homes (Conradie & Charlton. 1992 ). Historically, South African nursing bodies have not recognized these workers and have opposed formal training that might equip them to perform tasks done by student nurses (enrolled nursing auxiliaries). In post-election South Africa new cadres of workers increasingly need to be trained and employed. as part and parcel of the goals of the Reconstruction and Development Programme (RDP). which includes not only training citizens but also creating work and career opportunities for all. To ascertain the present attitudes of national nursing bodies towards the training of carers. the South African Nursing Council and the South African Nursing Association were invited to reply to the proposals in Dr Tooke's brief. Their replies are published as rejoinders to the brief. Finally, this number of SAJG also carries its first book review. Valerie Moller reviews the new publication of US authors Steven M. Albert and Maria G. Cattell. titled Old age in global perspective: cross-cultural and cross-national views. The book, which adopts a multidisciplinary approach, presents ethnographic case studies and evidence from cross-national surveys to assess variation in the experience of ageing and old age. Møller concludes that Southern African readers will gain many insights from the book, to better understand the complexities of ageing in their own society.
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Date Issued: 1995

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Southern African Journal of Gerontology, volume 4, number 2, October 1995

- Ferreira, Monica (editor), Moller, Valerie, HSRC/UCT Centre for Gerontology

Authors: Ferreira, Monica (editor) , Moller, Valerie , HSRC/UCT Centre for Gerontology
Date: 1995
Subjects: Gerontology -- South Africa , Older people -- Care -- South Africa
Language: English
Type: Text
Identifier: vital:8071 , http://hdl.handle.net/10962/d1012864
Description: This special issue of SAJG on "The family and ageing in Africa" marks yet another step in the annals of the African Gerontological Society (AGES). The first major step was taken in December 1993 when the society held its first workshop in Accra, Ghana to discuss an agenda on ageing. The results of the workshop were published under the title Effective responses to ageing in Africa by the year 2000 (Apt, Bester & Insley, 1995). Twenty years ago it would have been an impossible task to assemble African scientists and social welfare practitioners to discuss the subject of ageing. Very little researched information existed then and many African governments were likely to assert that ageing was no problem in their country. Even in the 1980s a great deal of scepticism existed in Africa about the need for African gerontology research. Today, and taking a cue from the deliberations of the first AGES workshop, there is no country in our region that is not confronted with the negative impacts of development and urbanization as their country charts its route towards modernization. Even though an ageing agenda still has a low profile on the economic desks of many African governments, the realisation that there are indeed difficulties to be overcome regarding the care of elderly people in Africa is widespread.
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Date Issued: 1995

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Staff development policy

- Chemical Workers Industrial Union (CWIU)

Authors: Chemical Workers Industrial Union (CWIU)
Date: 1995
Subjects: CWIU
Language: English
Type: text
Identifier: http://hdl.handle.net/10962/170184 , vital:41866
Description: CWIU is committed to the development of all its staff members. Therefore all staff members will have the opportunity to further their skills and. education supported by the Union. 1.1. The primary objective is to ensure that the aims and objectives of the union are achieved through an efficient,effective and excellent staff; 1.2. In addition,the union believes that individual staff members should have the opportunity to realise their full potential; Therefore,in implementing a Staff Development policy a balance will be achieved between organisational needs,which are primary,and personal needs of staff members.
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Date Issued: 1995

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Strategic plan for the restructuring of the textile and clothing industries

- SACTWU

Authors: SACTWU
Date: 1995
Subjects: SACTWU
Language: English
Type: text
Identifier: http://hdl.handle.net/10962/176444 , vital:42695
Description: The achievement of international competitiveness within a 10 year time frame with: a minimisation of the loss of job opportunities in the textile industry, the growth and net creation of jobs in the clothing sector, both formal and informal, successful, in general, export-orientated textile and clothing industries, the acceptance by the industries of a greater responsibility for their own future by lessening their dependence on government by improving productivity through human resource development, work organisation and upgraded technology; a conscious move out of the lower end of the market but simultaneous efforts to retain these activities within the region; and a competitive environment where everyone gains, including the consumer, by making basic goods more affordable.
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Date Issued: 1995

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Structural studies on the capsular antigens of some Escherichia coli serotypes

- Leslie, Margaret Ruth

Authors: Leslie, Margaret Ruth
Date: 1995
Subjects: Escherichia Polysaccharides Antigens Enterobacteriaceae
Language: English
Type: Thesis , Doctoral , PhD
Identifier: vital:3767 , http://hdl.handle.net/10962/d1003245
Description: The research presented in this thesis forms part of an on-going collaborative programme concerned with the determination of the chemical structures of the surface antigens of bacteria belonging to genera within the family Enterobacteriaceae. Bacteria of this family are opportunistic pathogens and are frequently responsible for serious infections in animals and man. Surface antigens produced by virulent strains are largely polysaccharides and occur as lipopolysaccharides (the O-antigens) and capsular polysaccharides (the K-antigens) respectively. The extracellular polysaccharide antigens expressed by strains of the species Escherichia coli are of considerable . interest due to their effect on immunological processes and the relationship which exists between their chemical structure and virulence. To date, some seventy-four K-antigens have been distinguished serologically within the species E. coli and structures have been determined for most of these. The K-antigens of E. coli are structurally diverse and exhibit serological cross-reactivity with other pathogenic bacteria. The structures of five previously unstudied E. coli K-antigens, viz. those produced by serotypes 020:K1 01 :H-, 08:K45:H9, 08:K50:H-, 0101 :K1 03:H-, and 08:K43:H11, are presented in this thesis. A variety of chemical techniques has been employed in the structural analysis, and these are discussed. Two-dimensional NMR spectroscopic techniques proved invaluable for the structural elucidation of these complex carbohydrates, and high-field NMR spectroscopy alone was used in the analysis of the K43 antigen. Structural analysis of the K1 03 antigen was facilitated by specific enzymatic degradation, using a bacteriophage-borne endoglycanase. The K45 antigen was found to contain the unusual sugar 3-acetamido-3,6-dideoxygalactopyranose, while the K50 and K103 antigens join a minority group of polysaccharides which contain pyruvate as their only acidic component.
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Date Issued: 1995

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